Table of Contents

Table of Contents

Columbia Funds Series Trust

Columbia Global Strategic Equity Fund

Columbia Select Global Growth Fund

Columbia Funds Series Trust I

Columbia Disciplined Small Core Fund

Columbia Funds Series Trust II

Columbia Small/Mid Cap Value Fund

Columbia Contrarian Europe Fund

(Each, a “Target Fund” and collectively, the “Target Funds”)

IMPORTANT NOTICE OF INTERNET AVAILABILITY OF

COMBINED INFORMATION STATEMENT/PROSPECTUS

This notice presents only an overview of the more complete Combined Information Statement/Prospectus that is available to you on the Internet relating to the reorganization (each, a “Reorganization” and collectively, the “Reorganizations”) of each Target Fund into another fund (each, an “Acquiring Fund” and together, the “Acquiring Funds”) managed by Columbia Management Investment Advisers, LLC (“Columbia Threadneedle”). The Target Funds and Acquiring Funds are referred to collectively as the “Funds.” As previously communicated in a supplement to your Fund’s prospectus, Columbia Threadneedle proposed the Reorganizations to the boards of trustees of the Target Funds and the Acquiring Funds (the “Boards”) and the Boards unanimously approved each Reorganization. In accordance with each Fund’s Declaration of Trust and applicable state and U.S. federal law (including Rule 17a-8 under the Investment Company Act of 1940), each Reorganization may be effected without the approval of shareholders of a Fund. Although shareholder approval is not required for the Reorganization of your Fund, we encourage you to access and review all of the important information contained in the Combined Information Statement/Prospectus.

Under the Agreement and Plan of Reorganization, each Target Fund, as indicated below, will transfer that portion of its assets attributable to each class of its shares (in aggregate, all of its assets) to the corresponding Acquiring Fund, as indicated below, in exchange for shares of a corresponding class of shares of the Acquiring Fund and the assumption by the Acquiring Fund of all the liabilities of the corresponding Target Fund. Each Reorganization is expected to close on or about July 11, 2020. If you are a shareholder of the Target Fund immediately prior to the closing on that date, you will become a shareholder of the corresponding Acquiring Fund.

The table below shows each Target Fund and the corresponding Acquiring Fund for each Reorganization:

Columbia Threadneedle proposed the Reorganizations in order to streamline the product offerings of the mutual funds managed by Columbia Threadneedle and its affiliates (the “Columbia Funds”), so that management, distribution and other resources can be focused more effectively on a smaller group of Columbia Funds. The Reorganization of each Target Fund into the Acquiring Fund will enable shareholders of each Target Fund to invest in a larger, potentially more efficient portfolio while continuing to pursue a similar investment objective.

Instead of physically delivering the Combined Information Statement/Prospectus, Columbia Threadneedle has made the Combined Information Statement/Prospectus available to you online at [•] until [•], 2020. A paper or email copy of the Combined Information Statement/Prospectus may be obtained, without charge, by calling Computershare Fund Services, toll free at (888) 916-1754.

Table of Contents

Only one copy of this notice may be delivered to shareholders of a Target Fund who reside at the same address, unless the Target Fund has received instructions to the contrary. If you would like to receive an additional copy, please write to Computershare Fund Services, c/o Operation Department, 280 Oser Avenue, Hauppauge, NY 11788, or call (888) 916-1754. Shareholders wishing to receive separate copies of a Target Fund’s notices in the future, and shareholders sharing an address who wish to receive a single copy if they currently are receiving multiple copies, should also contact the Fund.

NO SHAREHOLDER VOTE WILL BE TAKEN WITH RESPECT TO THE MATTERS DESCRIBED IN THIS IMPORTANT NOTICE OF INTERNET AVAILABILITY OF COMBINED INFORMATION STATEMENT/PROSPECTUS. WE ARE NOT ASKING YOU FOR A PROXY AND YOU ARE REQUESTED NOT TO SEND US A PROXY.

If you have any questions, please contact Computershare Fund Services, toll free at (888) 916-1754.

Table of Contents

Columbia Funds Series Trust

Columbia Global Strategic Equity Fund

Columbia Select Global Growth Fund

Columbia Funds Series Trust I

Columbia Disciplined Small Core Fund

Columbia Funds Series Trust II

Columbia Small/Mid Cap Value Fund

Columbia Contrarian Europe Fund

COMBINED INFORMATION STATEMENT/PROSPECTUS

[•], 2020

Columbia Management Investment Advisers, LLC (“Columbia Threadneedle”) has recommended a series of mutual fund liquidations and reorganizations as part of an initiative to streamline the product offerings of the mutual funds managed by Columbia Threadneedle and its affiliates (the “Columbia Funds”). As part of this initiative, the boards of trustees of the funds listed above (each, a “Target Fund” and collectively, the “Target Funds”) have approved proposals to reorganize each of the Target Funds into another fund managed by Columbia Threadneedle (each, an “Acquiring Fund” and together, the “Acquiring Funds”). The Target Funds and Acquiring Funds are referred to collectively as the “Funds.” No shareholder approval is required to effect the reorganization of the Target Funds into the corresponding Acquiring Funds (each a “Reorganization” and collectively, the “Reorganizations”), which are expected to be completed on or about July 11, 2020.

This is a brief overview of the Reorganization of your Target Fund. We encourage you to read the full text of the enclosed Combined Information Statement/Prospectus to obtain detailed information with respect to the Reorganization of your Target Fund. THE FUNDS ARE NOT ASKING YOU FOR A PROXY AND YOU ARE REQUESTED NOT TO SEND A PROXY TO THE FUNDS WITH RESPECT TO THE REORGANIZATIONS.

Q: What information is included in the Combined Information Statement/Prospectus?

The enclosed Combined Information Statement/Prospectus provides information about the Reorganization of your Target Fund, and information about the shares that you will receive as a result of the Reorganization. Although the Combined Information Statement/Prospectus includes information that you should review and keep for future reference, it is not a solicitation of a proxy from you.

Q: What is a fund reorganization?

A fund reorganization involves one fund transferring all of its assets and liabilities to another fund in exchange for shares of such fund. Once completed, shareholders of the fund being reorganized will hold shares of the acquiring fund.

Q: Do I need to take any action in connection with the Reorganizations?

No. In accordance with each Fund’s Declaration of Trust and applicable state and U.S. federal law (including Rule 17a-8 under the Investment Company Act of 1940), each Reorganization may be effected without the approval of shareholders of a Fund. Your shares will automatically be converted into shares of the Acquiring Fund on the date of the completion of the Reorganization for your Fund. You will receive written confirmation that this change has taken place. No certificates for shares will be issued in connection with the Reorganizations. The aggregate net asset value (the “NAV”) of the Acquiring Fund shares you receive in the Reorganization will be equal to the aggregate NAV of the shares you own in the applicable Target Fund immediately prior to such Reorganization. If you sell your shares or are otherwise no longer a shareholder of the Target Fund as of the closing, this transaction will not impact you.

Table of Contents

Q: Which funds are being reorganized?

The Combined Information Statement/Prospectus provides information about the Reorganization of the Target Funds into the Acquiring Funds, as noted in the table below:

Q: Will the portfolio manager of my Target Fund change as a result of the Reorganizations?

Yes. The portfolio managers of each Acquiring Fund are different than the portfolio managers for each Target Fund. The portfolio managers of each Acquiring Fund will continue to manage the Acquiring Funds following the Reorganizations. Columbia Threadneedle is the investment manager of each Target Fund and each Acquiring Fund.

Q: Will there be any changes to the options or services associated with my account as a result of the Reorganizations?

No. Account-level features and options such as dividend distributions, dividend diversification, automatic investment plans, systematic withdrawals and dollar cost averaging currently set up with your Target Fund for your Target Fund account will automatically carry over from accounts in each Target Fund to accounts in the Acquiring Fund. If you purchase shares through a broker-dealer or other financial intermediary, please contact your financial intermediary for additional details.

Q: Are there costs of the Reorganizations?

You will not pay any sales charges in connection with Acquiring Fund shares issued in the Reorganizations. Reorganization costs will be allocated among the Funds as described in the Combined Information Statement/Prospectus, but will be limited to an amount that is not more than the anticipated reduction in expenses borne by a Fund’s shareholders during the first year following the Reorganization. Any amounts in excess of this limit will be borne by Columbia Threadneedle. Reorganization costs do not include any repositioning costs arising from sales of portfolio assets by the Target Fund before the Reorganization or by the Acquiring Fund after the Reorganization, which costs will be borne by the applicable Fund. Repositioning costs are discussed in the section of the Combined Information Statement/Prospectus entitled “Section A — Reorganizations — Synopsis — Comparison of Fees and Expenses — Portfolio Turnover” with respect to each Reorganization.

Q: What are the U.S. federal income tax consequences of the Reorganizations?

Each Reorganization is expected to qualify as a tax-free reorganization for U.S. federal income tax purposes. Accordingly, it is expected that Target Fund shareholders will not, and the Target Fund generally will not, recognize gain or loss as a direct result of a Reorganization, as described in more detail in the section of the Combined Information Statement/Prospectus entitled “Section B — Additional Information about Each Reorganization — U.S. Federal Income Tax Status of the Reorganizations.” A portion of the portfolio assets of a Target Fund may be sold by the Target Fund prior to its Reorganization or by the Acquiring Fund following the Reorganization. Any such sales will cause such Target Fund or Acquiring Fund, as applicable, to incur transaction costs and may result in a taxable distribution to shareholders. Additionally, because each Reorganization will end the tax year of the applicable Target Fund, it will accelerate distributions to shareholders from the Target Fund for its tax year ending on the date of the Reorganization. Those tax year-end distributions will be taxable, and will include any distributable, but not previously distributed, income and capital gains resulting from portfolio turnover prior to consummation of the Reorganization.

Table of Contents

Q: Will there be any changes to my fees and expenses as a result of the Reorganizations?

It is expected that, following the Reorganizations, the expenses borne by Target Fund shareholders as shareholders of the Acquiring Fund will generally be lower than the expenses they currently bear, as described in detail in the sections of the Combined Information Statement/Prospectus entitled “Fees and Expenses” contained in the synopsis of each Reorganization in “Section A — Reorganizations.”

Q: Whom should I call if I have questions?

If you have questions about any of the Reorganizations described in the Combined Information Statement/Prospectus, please call Computershare Fund Services, toll free at (888) 916-1754. Shareholders of Target Funds for which a Reorganization is effected within 60 days following the completion of its fiscal year or half year may call (800) 345-6611 to request a copy of the Target Fund’s final report to shareholders for that period.

Table of Contents

[•], 2020

Dear Shareholder,

As President of the Target Funds listed below, I am writing to provide important information about reorganizations that will affect your investment in one or more Target Funds. As previously communicated in a supplement to your Target Fund’s prospectus, Columbia Management Investment Advisers, LLC (“Columbia Threadneedle”), the Target Funds’ investment manager, proposed to the boards of trustees of the Target Funds (the “Boards”) the reorganization of certain funds managed by Columbia Threadneedle (each, a “Reorganization” and collectively, the “Reorganizations”), and the Boards unanimously approved the Reorganizations.

The enclosed Combined Information Statement/Prospectus provides information about the Reorganizations of the Target Funds into other corresponding funds (each, an “Acquiring Fund” and together, the “Acquiring Funds”) managed by Columbia Threadneedle. Under the Agreement and Plan of Reorganization, each Target Fund will transfer that portion of its assets attributable to each class of its shares (in aggregate, all of its assets) to the corresponding Acquiring Fund, as indicated below, in exchange for shares of the corresponding class of shares of the Acquiring Fund and the assumption by the Acquiring Fund of all the liabilities of the Target Fund. Each Reorganization is expected to close on or about July 11, 2020.

The table below shows each Target Fund and the corresponding Acquiring Fund for each Reorganization:

Columbia Threadneedle proposed the Reorganizations in order to streamline the product offerings of the mutual funds managed by Columbia Threadneedle and its affiliates (the “Columbia Funds”), so that management, distribution and other resources can be focused more effectively on a smaller group of Columbia Funds. The Reorganization of each Target Fund into the Acquiring Fund will enable shareholders of each Target Fund to invest in a larger, potentially more efficient portfolio while continuing to pursue a similar investment objective.

NO ACTION ON YOUR PART IS REQUIRED TO EFFECT A REORGANIZATION. Your shares will automatically be converted into shares of the Acquiring Fund on the date of the completion of the Reorganization for your fund. We are not asking you for a proxy and you are requested not to send us a proxy.

Please carefully read the enclosed Combined Information Statement/Prospectus, as it discusses the Reorganizations in more detail. If you sell your shares or are otherwise no longer a shareholder of the Target Fund as of the closing date, this transaction will not impact you. If you have questions, please call Computershare Fund Services, toll free at (888) 916-1754.

Sincerely,

Christopher O. Petersen President, Columbia Funds

Table of Contents

The information contained in this Combined Information Statement/Prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This Combined Information Statement/Prospectus is not an offer to sell these securities, and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION,

DATED FEBRUARY 26, 2020

Columbia Funds Series Trust

Columbia Global Strategic Equity Fund

Columbia Select Global Growth Fund

Columbia Funds Series Trust I

Columbia Disciplined Small Core Fund

Columbia Funds Series Trust II

Columbia Small/Mid Cap Value Fund

Columbia Contrarian Europe Fund

(Each, a “Target Fund” and collectively, the “Target Funds”)

COMBINED INFORMATION STATEMENT/PROSPECTUS

Dated [•], 2020

Important Notice Regarding the Availability of this Combined Information Statement/Prospectus:

This Combined Information Statement/Prospectus is available at [•]

This document is an information statement for each Target Fund and a prospectus for each Acquiring Fund (as defined below). The mailing address and telephone number of each Target Fund and each Acquiring Fund (each, a “Fund” and collectively, the “Funds”) is c/o Columbia Management Investment Services Corp., P.O. Box 219104, Kansas City MO 64121-9104 and 800-345-6611. This Combined Information Statement/Prospectus contains information you should know about the reorganizations (each, a “Reorganization” and collectively, the “Reorganizations”), with respect to your Target Fund, as indicated below. You should read this document carefully and retain it for future reference.

The Important Notice of Internet Availability of Combined Information Statement/Prospectus is being mailed on or about [•]. This Combined Information Statement/Prospectus is available at [•] until [•], 2020. A paper or email copy of this Combined Information Statement/Prospectus may be obtained, without charge, by calling Computershare Fund Services, toll free at (888) 916-1754.

NO SHAREHOLDER VOTE WILL BE TAKEN WITH RESPECT TO THE MATTERS DESCRIBED IN THIS COMBINED INFORMATION STATEMENT/PROSPECTUS. WE ARE NOT ASKING YOU FOR A PROXY AND YOU ARE REQUESTED NOT TO SEND US A PROXY. In accordance with each Fund’s Declaration of Trust and applicable state and U.S. federal law (including Rule 17a-8 under the Investment Company Act of 1940), each Reorganization may be effected without the approval of shareholders of a Fund.

Each of the Funds is a registered open-end management investment company (or a series thereof).

Where to Get More Information

The following documents have been filed with the Securities and Exchange Commission (the “SEC”) and are incorporated into this Combined Information Statement/Prospectus by reference:

Columbia Global Strategic Equity Fund (SEC file no. 811-09645)

Table of Contents

Columbia Select Global Growth Fund (SEC file no. 811-09645)

Columbia Small/Mid Cap Value Fund (SEC file no. 811-21852)

Columbia Contrarian Europe Fund (SEC file no. 811-21852)

Columbia Disciplined Small Core Fund (SEC file no. 811-04367)

Table of Contents

For a free copy of any of the documents listed above and/or to ask questions about this Combined Information Statement/Prospectus, please call Computershare Fund Services, toll free at (888) 916-1754.

Each of the Funds is subject to the information requirements of the Securities Exchange Act of 1934, as amended, and the Investment Company Act of 1940, as amended (the “1940 Act”), and files reports, proxy materials and other information with the SEC. Copies of these reports, proxy materials and other information may be obtained, after paying a duplicating fee, by electronic request at publicinfo@sec.gov, or by writing to the Public Reference Branch of the SEC Office of Consumer Affairs and Information Services, 100 F Street, N.E., Washington, D.C. 20549-0102. In addition, copies of these documents may be viewed online or downloaded from the SEC’s website at www.sec.gov.

Please note that investments in the Funds are not bank deposits, are not federally insured, are not guaranteed by any bank or government agency and may lose value. There is no assurance that any Fund will achieve its investment objectives.

AS WITH ALL MUTUAL FUNDS, THE SEC HAS NOT APPROVED OR DISAPPROVED THESE SECURITIES OR PASSED ON THE ADEQUACY OF THIS COMBINED INFORMATION STATEMENT/PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

Table of Contents

TABLE OF CONTENTS

-i-

Table of Contents

TABLE OF CONTENTS

(continued)

-ii-

Table of Contents

SECTION A — REORGANIZATIONS

The following information describes the proposed Reorganization of each Target Fund (as defined below) into the corresponding Acquiring Fund (as defined below) (each, a “Reorganization” and collectively, the “Reorganizations”).

SUMMARY

Columbia Management Investment Advisers, LLC (“Columbia Threadneedle” or the “Investment Manager”) has recommended a series of mutual fund liquidations and reorganizations as part of an initiative to streamline the product offerings of the mutual funds managed by Columbia Threadneedle and its affiliates (the “Columbia Funds”). As part of this initiative, the boards of trustees (each, a “Board” and collectively, the “Boards”) of Columbia Global Strategic Equity Fund, Columbia Select Global Growth Fund, Columbia Small/Mid Cap Value Fund, Columbia Contrarian Europe Fund, and Columbia Disciplined Small Core Fund (each, a “Target Fund” and collectively, the “Target Funds”) have approved proposals to reorganize each of the Target Funds into another fund managed by Columbia Threadneedle (each, an “Acquiring Fund” and together, the “Acquiring Funds”). The Target Funds and Acquiring Funds are collectively referred to as the “Funds.” Each Reorganization is expected to close on or about July 11.

This Combined Information Statement/Prospectus provides information about the Reorganization of each Target Fund into the corresponding Acquiring Fund. The following is a summary of the Reorganizations. More complete information appears later in this Combined Information Statement/Prospectus. You should carefully read the entire Combined Information Statement/Prospectus and the exhibits because they contain details that are not included in this summary.

How Each Reorganization Will Work

1

Table of Contents

U.S. Federal Income Tax Consequences

Each Reorganization is expected to qualify as a tax-free reorganization for U.S. federal income tax purposes and will not take place unless the Target Fund and the corresponding Acquiring Fund receive a satisfactory opinion of tax counsel substantially to the effect that the Reorganization will qualify as a tax-free reorganization, as described in more detail in the section entitled “Section B — Additional Information about Each Reorganization — U.S. Federal Income Tax Status of the Reorganizations.” Accordingly, subject to the limited exceptions described in that section, no gain or loss is expected to be recognized by any Target Fund or its shareholders as a direct result of its Reorganization. A portion of the portfolio assets of a Target Fund may be sold by the Target Fund prior to its Reorganization or by the corresponding Acquiring Fund after a Reorganization. The actual tax effect of such sales will depend on the difference between the price at which such portfolio assets are sold and the tax basis of the selling Fund in such assets and the holding period of such assets. Any capital gains recognized in any such sales on a net basis, after reduction by any available capital losses, will be distributed to shareholders as capital gain dividends (to the extent of net realized long-term capital gains over net realized short-term capital losses) and/or ordinary dividends (to the extent of net realized short-term capital gains over net realized long-term capital losses) during or with respect to the year of sale, and such distributions will be taxable to shareholders. Additionally, because each Reorganization will end the tax year of the applicable Target Fund, it will accelerate distributions to shareholders from the Target Fund for its tax year ending on the date of the Reorganization. Those tax year-end distributions will be taxable, and will include any distributable, but not previously distributed, income and capital gains resulting from portfolio turnover prior to consummation of the Reorganization. At any time prior to a Reorganization, a shareholder may redeem shares of a Target Fund. Any such redemption would likely result in the recognition of gain or loss by the shareholder for U.S. federal income tax purposes. If a shareholder holds Target Fund shares in a non-taxable account, distributions and redemption proceeds with respect to those shares will not be currently taxable to the shareholder if those amounts remain in the non-taxable account.

A Target Fund shareholder’s aggregate tax basis in the Acquisition Shares is expected to carry over from the shareholder’s Target Fund shares, and a Target Fund shareholder’s holding period in the Acquisition Shares is expected to include the shareholder’s holding period in the Target Fund shares.

For more information about the U.S. federal income tax consequences of the Reorganizations, see the section entitled “Section B — Additional Information about Each Reorganization — U.S. Federal Income Tax Status of the Reorganizations.” For more information regarding repositioning costs, see the section captioned “portfolio turnover” within the synopsis for each Reorganization.

2

Table of Contents

Costs of the Reorganizations

Each Target Fund and Acquiring Fund may bear a portion of the out-of-pocket expenses associated with its Reorganization. With respect to each Reorganization, the Acquiring Fund will bear the costs of certain reorganization-related testing conducted by the Fund’s auditors in connection with the Reorganization. All other Reorganization costs will be allocated among the Target Funds in accordance with the Agreement. Reorganization costs include, but are not limited to: (1) the expenses associated with the preparation, printing and mailing of this Combined Information Statement/Prospectus, (2) the preparation of the registration statement and other shareholder communications and any filings with the Securities and Exchange Commission (the “SEC”) and/or other governmental authorities in connection with the Reorganizations; and (3) legal, audit, custodial and other fees incurred in connection with the Reorganizations (“Reorganization Costs”). Fees and expenses incurred directly by a Target Fund are allocated to that Fund. Fees and expenses incurred on behalf of multiple Target Funds, such as legal fees and the costs of preparing the Combined Information Statement/Prospectus, will be allocated among participating Target Funds equally. The Funds will bear Reorganization Costs to the extent that such fees and expenses do not exceed the anticipated reduction in expenses that shareholders of a Fund will realize in the first year following the Reorganization. Any amounts in excess of this limit will be borne by Columbia Threadneedle. Should any Reorganization fail to occur, Columbia Threadneedle will bear all costs associated with that Reorganization.

The estimated Reorganization Costs expected to be borne by each Target Fund and each Acquiring Fund are set forth below as of the fiscal period for each Acquiring Fund shown in the Fee and Expense sections below:

Based on the operating expense ratios shown in the Fees and Expenses section below for each Acquiring Fund, it is projected that, after the Reorganizations, each class of each Target Fund will benefit from expense savings that will offset the allocated Reorganization expenses. However, the benefit of those projected expense savings will not be realized immediately. The allocated Reorganization expenses of a Target Fund will not exceed the anticipated reduction in expenses for such Target Fund’s shareholders (as shareholders of the Acquiring Fund following the Reorganization) in the first year following the Reorganization.

If a Target Fund shareholder redeems his or her Acquisition Shares during the first year following the Reorganization, the shareholder may not fully benefit from the projected expense savings.

3

Table of Contents

SYNOPSIS OF REORGANIZATION 1: COMPARISON OF COLUMBIA GLOBAL STRATEGIC EQUITY FUND AND COLUMBIA CAPITAL ALLOCATION AGGRESSIVE PORTFOLIO

Comparison of the Target Fund and the Acquiring Fund

The Target Fund and the Acquiring Fund:¹

Comparison of Fees and Expenses

The following tables describe the fees and expenses that you may pay if you buy and hold shares of the Funds. The purpose of the tables below is to assist you in understanding the various costs and expenses of investing in common shares of the Funds. An investor transacting in a class of Fund shares without any front-end sales charge, contingent deferred sales charge, or other asset-based fee for sales or distribution may be required to pay a commission to the financial intermediary for effecting such transactions. Such commission rates are set by the financial intermediary and are not reflected in the tables or the example below. You may qualify for sales charge discounts if you and members of your immediate family invest, or agree to invest in the future, at least $50,000 in certain classes of shares of eligible funds distributed by Columbia Management Investment Distributors, Inc. (the “Distributor”).

The information in the table reflects the fees and expenses for each Fund’s six-month semi-annual period ended July 31, 2019 (annualized) and the pro forma expenses for the twelve months ended July 31, 2019 for the combined fund following the Reorganization.

4

Table of Contents

5

Table of Contents

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

Expense Examples: These examples are intended to help you compare the cost of investing in each Fund with the cost of investing in other mutual funds. These examples assume that you invest $10,000 in the applicable Fund for the time periods indicated and then redeem all of your shares at the end of those periods, both under the current arrangements and, for the Acquiring Fund, assuming completion of the proposed Reorganization. These examples also assume that your investment has a 5% return each year and that each Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on those assumptions your costs would be:

6

Table of Contents

If you owned or will own any class of shares other than Class C shares, you would pay the same costs shown in the tables above if you did not redeem your shares at the end of the periods indicated. If you owned or will own Class C shares, you would pay the following costs if you did not redeem your shares at the end of the periods indicated, which may be different than the costs shown in the tables above.

Portfolio Turnover. Each Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. Those costs, which are not reflected in annual Fund operating expenses or in the expense examples, affect a Fund’s performance. During the most recent fiscal year, each Fund’s portfolio turnover rate was the following percentage of the average value of the Fund’s portfolio:

A portion of the Target Fund’s portfolio assets are expected to be sold prior to its Reorganization by the Target Fund and after the Reorganization by the Acquiring Fund. If the Reorganization had occurred as of September 30, 2019, it is estimated that approximately 8% of the Target Fund’s investment portfolio would have been sold by the Target Fund before the Reorganization and approximately 38% of the Target Fund’s investment portfolio would have been sold by the Acquiring Fund after the Reorganization. Because the Funds invest primarily in other funds, the Funds are not anticipated to incur brokerage or transaction costs. Capital gains from such portfolio sales may result in increased distributions of net capital gain and net investment income. If such sales occurred as of September 30, 2019, the sales would have resulted in increased distributions of net capital gain and net investment income to Target Fund shareholders of approximately $0.14 per share and to Acquiring Fund shareholders (including shareholders of the Target Fund following the Reorganization) of approximately $0.36 per share.

7

Table of Contents

Comparison of Investment Objectives, Principal Investment Strategies, and Fundamental and Non-Fundamental Investment Policies

The investment objectives and principal investment strategies of the Target Fund and the Acquiring Fund, are set forth in the table below.

The Target Fund’s investment policy with respect to 80% of its net assets may be changed by the Fund’s Board without shareholder approval as long as shareholders are given 60 days’ advance written notice of the change.

While the Target Fund and the Acquiring Fund have generally similar investment objectives and principal investment strategies, there are some differences. Each Fund is a fund-of funds that invests primarily in Underlying Funds that provide exposure primarily to equity securities. The Target Fund invests in affiliated and third-party funds while the Acquiring Fund invests primarily in affiliated funds. See below for a more detailed comparison.

8

Table of Contents

Additional Information About the Funds’ Principal Investment Strategies

Target Fund. Columbia Threadneedle chooses investments for the Target Fund by:

Columbia Threadneedle may sell investments: to adjust the allocation of the Fund’s assets; if Columbia Threadneedle believes that an investment is no longer a suitable investment; or that other investments are more attractive; to meet redemption requests; or for other reasons. When selling shares to meet redemption requests, Columbia Threadneedle normally will, to the extent feasible, sell a proportionate amount of the shares the Fund owns in each Underlying Fund and instrument.

Acquiring Fund. Under normal circumstances, the Acquiring Fund may invest, directly or indirectly, in each of equity, fixed income and cash/cash equivalent asset classes and alternative strategies (each, an “asset class category” and collectively, the “asset class categories”) within the following target asset allocation range (includes investments in Underlying Funds and the other securities described in the 20% Sleeve):

9

Table of Contents

Columbia Threadneedle uses an asset allocation strategy designed to:

Columbia Threadneedle regularly reviews asset class allocations and allocations to Underlying Funds, as well as security selection within the 20% Sleeve. Columbia Threadneedle may reallocate, including on a daily basis, the Fund’s investments in the Underlying Funds and/or the 20% Sleeve to return the Fund to targeted allocations, or to tactically adjust the Fund’s market or other exposures based on market or other circumstances. Derivatives, in particular, may be used tactically to increase or decrease the Fund’s exposure to the market or a given market segment, industry, or position.

Comparison of Fundamental Investment Policies

Each Fund has adopted certain fundamental and non-fundamental investment restrictions. The fundamental investment restrictions (i.e., those which may not be changed without shareholder approval) are listed below.

The fundamental investment restrictions cannot be changed without the consent of the holders of a majority of the outstanding shares of the applicable Fund. The term “majority of the outstanding shares” means the vote of (i) 67% or more of a Fund’s shares present at a meeting, if more than 50% of the outstanding shares of the Fund are present or represented by proxy, or (ii) more than 50% of a Fund’s outstanding shares, whichever is less.

10

Table of Contents

11

Table of Contents

The Acquiring Fund’s investment objectives, principal investment strategies, fundamental and non-fundamental investment policies and holdings may expose the Target Fund’s shareholders to new or increased risks. A comparison of the principal risks of investing in the Target Fund and the Acquiring Fund is provided under “Comparison of Principal Risks” below.

Comparison of Principal Risks

The Acquiring Fund is subject to the principal risks described in “Section C — Additional Information Applicable to the Acquiring Funds” below. The Funds are subject to many of the same principal risks, but differ primarily given that the Target Fund is subject to risks associated with its investments in foreign securities (including depositary receipts risk, emerging market securities risk, foreign currency risk, and sovereign debt risk), while the Acquiring Fund does not identify foreign investment risk as a principal risk. In addition, unlike the Target Fund, the Acquiring Fund is also subject to high yield investment risk, and risks associated with its exposure to derivatives, including forward contracts risk and options risk. Unlike the Acquiring Fund, the Target Fund is subject to risks associated with its investment in certain types of securities (including commodity-related investment risk, convertible securities risk, preferred stock risk, regulatory risk associated with alternative investments, and special situations risk), liquidity risk, quantitative model risk and sector risk. The actual risks of investing in each Fund depend on the Underlying Funds selected, the percentage allocation to the Underlying Funds, and other securities held in each Fund’s portfolio and on market conditions, all of which change over time.

Comparison of Management of the Funds

Columbia Threadneedle serves as investment manager for each Fund. Both Funds obtain investment management services from Columbia Threadneedle according to the terms of advisory agreements that are substantially similar. The table below shows the current contractual management fee schedule for each of the Funds. The effective management fee of each Fund as of January 31, 2019 was 0.10% for the Target Fund and 0.08% for the Acquiring Fund. The Acquiring Fund’s management fee schedule will apply following completion of the Reorganization.

12

Table of Contents

Each Fund is governed by its Board, which is responsible for overseeing the Fund. For a listing of the members comprising each Fund’s Board, please refer to the Statement of Additional Information for the relevant Fund.

The Funds have different portfolio management teams. “Section C — Additional Information Applicable to the Acquiring Funds” below describes the employment history of the portfolio managers of the Acquiring Fund. The Statement of Additional Information of each Fund provides additional information about portfolio manager compensation, other accounts managed and ownership of each Fund’s shares.

Comparison of Performance

The following bar charts and tables show, respectively:

These bar charts and tables show some of the risks of investing in the Funds. The bar charts shows how each Fund’s Class A share performance (without sales charges) has varied for each full calendar year shown. If the sales charges were reflected, returns shown would be lower. The table below the bar chart compares each Fund’s returns (after applicable sales charges shown in the fees tables above) for the periods shown with a broad measure of market performance, as well as another measure of performance for markets in which the Acquiring Fund may invest.

The performance of one or more share classes shown in the tables below begins before the indicated inception date for such share class. The returns shown for each such share class include the returns of each Fund’s Class A shares (without applicable sales charges and adjusted to reflect the higher class-related operating expenses of such share classes, where applicable) for periods prior to its inception date. Share classes with expenses that are higher than Class A shares will have performance that is lower than Class A shares (without applicable sales charges). Except for differences in annual returns resulting from differences in expenses and sales charges (where applicable), each share class of the same Fund would have substantially similar annual returns because all share classes of such Fund invest in the same portfolio of securities.

The after-tax returns shown in the Average Annual Total Returns tables below are calculated using the highest historical individual U.S. federal marginal income tax rates in effect during the period indicated in the tables and do not reflect the impact of state, local or foreign taxes. Your actual after-tax returns will depend on your personal tax situation and may differ from those shown in the tables. In addition, the after-tax returns shown in the tables do not apply to shares held in tax-advantaged accounts such as 401(k) plans or Individual Retirement Accounts (IRAs). The after-tax returns are shown only for Class A shares and will vary for other share classes.

The Target Fund’s performance prior to June 2, 2015 reflects returns achieved pursuant to different principal investment strategies. If the Fund’s current strategies had been in place for the prior periods, results shown may have been different.

13

Table of Contents

Each Fund’s past performance (before and after taxes) is no guarantee of how such Fund will perform in the future. Updated performance information can be obtained by calling toll-free 800.345.6611 or visiting columbiathreadneedleus.com.

Columbia Global Strategic Equity Fund

CLASS A SHARE PERFORMANCE

(based on calendar years)

During the periods shown in the bar chart, the highest return for a calendar quarter was 13.24% (quarter ended March 31, 2019) and the lowest return for a calendar quarter was -17.29% (quarter ended September 30, 2011).

Average Annual Total Returns After Applicable Sales Charges (for periods ended December 31, 2019)

Columbia Capital Allocation Aggressive Portfolio

Class A SHARE PERFORMANCE

(based on calendar years)

During the periods shown in the bar chart, the highest return for a calendar quarter was 12.23% (quarter ended September 30, 2010) and the lowest return for a calendar quarter was -14.03% (quarter ended September 30, 2011).

Average Annual Total Returns After Applicable Sales Charges (for periods ended December 31, 2019)

14

Table of Contents

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares of the Funds through a broker-dealer or other financial intermediary (such as a bank), the Funds and its related companies – including the investment manager, the Distributor and Columbia Management Investments Services Corp. (the transfer agent) – may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your financial advisor to recommend the Fund over another investment. These potential conflicts of interest may be heightened with respect to broker-dealers owned by Ameriprise Financial and/or its affiliates. Ask your financial advisor or visit your financial intermediary’s website for more information.

15

Table of Contents

SYNOPSIS OF REORGANIZATION 2: COMPARISON OF COLUMBIA SELECT GLOBAL GROWTH FUND AND COLUMBIA SELECT GLOBAL EQUITY FUND

Comparison of the Target Fund and the Acquiring Fund

The Target Fund and the Acquiring Fund:²

Comparison of Fees and Expenses

The following tables describe the fees and expenses that you may pay if you buy and hold shares of the Funds. The purpose of the tables below is to assist you in understanding the various costs and expenses of investing in common shares of the Funds. An investor transacting in a class of Fund shares without any front-end sales charge, contingent deferred sales charge, or other asset-based fee for sales or distribution may be required to pay a commission to the financial intermediary for effecting such transactions. Such commission rates are set by the financial intermediary and are not reflected in the tables or the example below. You may qualify for sales charge discounts if you and members of your immediate family invest, or agree to invest in the future, at least $50,000 in certain classes of shares of eligible funds distributed by the Distributor.

The information in the table reflects the fees and expenses for the Target Fund’s six-month semi-annual period ended August 31, 2019 (annualized), the Acquiring Fund’s fiscal year ended October 31, 2019 and the pro forma expenses for the twelve months ended October 31, 2019 for the combined fund following the Reorganization.

16

Table of Contents

17

Table of Contents

18

Table of Contents

Expense Examples: These examples are intended to help you compare the cost of investing in each Fund with the cost of investing in other mutual funds. These examples assume that you invest $10,000 in the applicable Fund for the time periods indicated and then redeem all of your shares at the end of those periods, both under the current arrangements and, for the Acquiring Fund, assuming completion of the proposed Reorganization. These examples also assume that your investment has a 5% return each year and that each Fund’s operating expenses remain the same. These examples include a contractual fee waiver/expense reimbursement arrangement only for Columbia Select Global Equity Fund (Pro Forma) and only for the period indicated in the Fund’s Annual Fund Operating Expenses. Although your actual costs may be higher or lower, based on those assumptions your costs would be:

If you owned or will own any class of shares other than Class C shares, you would pay the same costs shown in the tables above if you did not redeem your shares at the end of the periods indicated. If you owned or will own Class C shares, you would pay the following costs if you did not redeem your shares at the end of the periods indicated, which may be different than the costs shown in the tables above.

Portfolio Turnover. Each Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. Those costs, which are not reflected in annual Fund operating expenses or in the expense examples, affect a Fund’s performance. During the most recent fiscal year, each Fund’s portfolio turnover rate was the following percentage of the average value of the Fund’s portfolio:

19

Table of Contents

A portion of the Target Fund’s portfolio assets may be sold by the Acquiring Fund after the Reorganization. If the Reorganization had occurred as of September 30, 2019, it is estimated that approximately 78% of the Target Fund’s investment portfolio would have been sold by the Acquiring Fund after the Reorganization. It is estimated that such portfolio repositioning would have resulted in brokerage commissions or other transaction costs at a rate of approximately 0.06% for the Acquiring Fund. These transaction costs represent expenses of the Acquiring Fund that will not be subject to the Acquiring Fund’s expense cap and will be borne by the Acquiring Fund and indirectly borne by the Acquiring Fund’s shareholders (including shareholders of the Target Fund following the Reorganization). Capital gains from such portfolio sales may result in increased distributions of net capital gain and net investment income. If such sales occurred as of September 30, 2019, the sales would have resulted in increased distributions of net capital gain and net investment income to Acquiring Fund shareholders (including shareholders of the Target Fund following the Reorganization) of approximately $0.34 per share. The repositioning may result in the Acquiring Fund selling securities in greater volumes or in a shorter period of time than it normally would, which may impact the market price received in such sales.

Comparison of Investment Objectives, Principal Investment Strategies, and Fundamental and Non-Fundamental Investment Policies

The investment objectives and principal investment strategies of the Target Fund and the Acquiring Fund are set forth in the table below.

The Acquiring Fund’s investment policy with respect to 80% of its net assets may be changed by the Fund’s Board without shareholder approval as long as shareholders are given 60 days’ advance written notice of the change.

While the Target Fund and the Acquiring Fund have generally similar principal investment strategies, there are certain differences, including that the Acquiring Fund invests, under normal circumstances, at least 80% of its net assets in equity securities, whereas the Target Fund does not have this requirement (but is substantially invested in equity securities normally). See below for a more detailed comparison.

20

Table of Contents

Additional Information About the Funds’ Principal Investment Strategies

Target Fund. In selecting investments for the Target Fund, Columbia Threadneedle considers, among other factors:

Fundamental analysis with risk management, including cross-correlation analysis, is used in identifying investment opportunities and constructing the Fund’s portfolio.

Columbia Threadneedle may sell a security when the security’s price reaches a target set by Columbia Threadneedle; if Columbia Threadneedle believes that there is deterioration in the issuer’s financial circumstances or fundamental prospects; if other investments are more attractive; or for other reasons.

Acquiring Fund. Columbia Threadneedle serves as the investment manager to the Fund and is responsible for oversight of the Fund’s subadviser, Threadneedle International Limited (“Threadneedle”), an indirect wholly-owned subsidiary of Ameriprise Financial, Inc., the parent company of Columbia Threadneedle.

In pursuit of the Acquiring Fund’s objective, Threadneedle chooses investments for the Fund by:

A number of factors may prompt the portfolio management team to sell securities. A sale may result from a change in the composition of the Fund’s benchmark or a change in sector strategy. A sale may also be prompted by factors specific to a stock, such as valuation or company fundamentals.

21

Table of Contents

Comparison of Fundamental Investment Policies

Each Fund has adopted certain fundamental and non-fundamental investment restrictions. The fundamental investment restrictions (i.e., those which may not be changed without shareholder approval) are listed below.

The fundamental investment restrictions cannot be changed without the consent of the holders of a majority of the outstanding shares of the applicable Fund. The term “majority of the outstanding shares” means the vote of (i) 67% or more of a Fund’s shares present at a meeting, if more than 50% of the outstanding shares of the Fund are present or represented by proxy, or (ii) more than 50% of a Fund’s outstanding shares, whichever is less.

22

Table of Contents

The Acquiring Fund’s investment objectives, principal investment strategies, fundamental and non-fundamental investment policies and holdings may expose the Target Fund’s shareholders to new or increased risks. A comparison of the principal risks of investing in the Target Fund and the Acquiring Fund is provided under “Comparison of Principal Risks” below.

Comparison of Principal Risks

The Acquiring Fund is subject to the principal risks described in “Section C — Additional Information Applicable to the Acquiring Funds” below. The Funds are subject to many of the same principal risks, but differ primarily given that the Target Fund, unlike the Acquiring Fund, is subject to risks associated with its investments in derivatives (including forward contracts risk), and sector risk associated with its investment in the consumer discretionary sector. The actual risks of investing in each Fund depend on the securities held in each Fund’s portfolio and on market conditions, both of which change over time.

Comparison of Management of the Funds

Columbia Threadneedle serves as investment manager for each Fund. Both Funds obtain investment management services from Columbia Threadneedle according to the terms of advisory agreements that are substantially similar, except for the fee rate. Columbia Threadneedle has engaged its affiliate, Threadneedle, as an investment subadviser to make the day-to-day investment decisions for the Acquiring Fund according to the terms of a subadvisory agreement, and is responsible for oversight of Threadneedle. The effective management fee as of each Fund’s most recent fiscal year end was 0.87% for the Target Fund and 0.87% for the Acquiring Fund. The Board of the Acquiring Fund has approved a new management fee schedule, contingent upon the completion of the

23

Table of Contents

Reorganization. The Acquiring Fund’s management fee schedule will apply following completion of the Reorganization. The table below shows the current contractual management fee schedule for each of the Funds and the new management fee schedule of the Acquiring Fund following the Reorganization.

Each Fund is governed by its Board, which is responsible for overseeing the Fund. For a listing of the members comprising each Fund’s Board, please refer to the Statement of Additional Information for the relevant Fund.

The Funds have different portfolio management teams. “Section C — Additional Information Applicable to the Acquiring Funds” below describes the employment history of the portfolio managers of the Acquiring Fund. The Statement of Additional Information of each Fund provides additional information about portfolio manager compensation, other accounts managed and ownership of each Fund’s shares.

Comparison of Performance

The following bar charts and tables show, respectively:

These bar charts and tables show some of the risks of investing in the Funds. The bar charts shows how each Fund’s Class A share performance (without sales charges) has varied for each full calendar year shown. If the sales charges were reflected, returns shown would be lower. The table below the bar chart compares each Fund’s returns (after applicable sales charges shown in the fees tables above) for the periods shown with a broad measure of market performance, as well as another measure of performance for a market in which the Target Fund may invest.

The performance of one or more share classes shown in the tables below begins before the indicated inception date for such share class. The returns shown for each such share class include the returns of each Fund’s Class A shares (without applicable sales charges and adjusted to reflect the higher class-related operating expenses of such share classes, where applicable) for periods prior to its inception date. Share classes with expenses that are higher than Class A shares will have performance that is lower than Class A shares (without applicable sales charges). Except for differences in annual returns resulting from differences in expenses and sales charges (where applicable), each share class of the same Fund would have substantially similar annual returns because all share classes of such Fund invest in the same portfolio of securities.

The after-tax returns shown in the Average Annual Total Returns tables below are calculated using the highest historical individual U.S. federal marginal income tax rates in effect during the period indicated in the tables and do not reflect the impact of state, local or foreign taxes. Your actual after-tax returns will depend on your personal tax situation and may differ from those shown in the tables. In addition, the after-tax returns shown in the tables do not apply to shares held in tax-advantaged accounts such as 401(k) plans or Individual Retirement Accounts (IRAs). The after-tax returns are shown only for Class A shares and will vary for other share classes.

24

Table of Contents

The Target Fund’s performance prior to November 2015, when Columbia Threadneedle assumed day-to-day portfolio management responsibilities over the Fund, reflects returns achieved by a subadviser that managed the Fund according to different principal investment strategies. If the Fund’s current strategies had been in place for the prior periods, results shown may have been different.

Each Fund’s past performance (before and after taxes) is no guarantee of how the Fund will perform in the future. Updated performance information can be obtained by calling toll-free 800.345.6611 or visiting columbiathreadneedleus.com.

Columbia Select Global Growth Fund

CLASS A SHARE PERFORMANCE

(based on calendar years)

During the periods shown in the bar chart, the highest return for a calendar quarter was 22.16% (quarter ended March 31, 2019) and the lowest return for a calendar quarter was -22.52% (quarter ended December 31, 2018).

Average Annual Total Returns After Applicable Sales Charges (for periods ended December 31, 2019)

25

Table of Contents

Columbia Select Global Equity Fund

CLASS A SHARE PERFORMANCE

(based on calendar years)

During the periods shown in the bar chart, the highest return for a calendar quarter was 15.97% (quarter ended September 30, 2010) and the lowest return for a calendar quarter was -20.26% (quarter ended September 30, 2011).

Average Annual Total Returns After Applicable Sales Charges (for periods ended December 31, 2019)